How to split a budget so the money lands on the night

First decide how the kit travels, because that sets everything

Before a single share is allocated: is this kit carried on foot, or does it come out of a car boot?

Carried kit pays for weight and packed size, and paying for them is legitimate — it is the whole reason the light end of the market exists. Kit that travels in a boot pays for comfort, durability and packed length, and paying for grams there is money thrown away. Splitting a budget without answering this question first is how people end up with a very light chair and a cold night.

Give the largest share to what decides the night

Two items decide whether you sleep: the mat and the shelter. In that order, which surprises people.

The mat’s R-value — quoted against ASTM F3340, the common test that made figures from different makers comparable — describes resistance to heat flow between you and the ground, and cold from underneath is what most people mistake for a bag that is not warm enough. Width belongs in the same decision, because shoulders and elbows off the edge of a narrow mat are not on the mat at all, whatever the rating says. And R-values add up: a closed-cell foam mat under an inflatable one is the cheapest way there is to change the number.

The shelter takes the other large share, and what it buys is a dry floor and a pitch you can actually make. Read the hydrostatic head twice — makers publish it separately for the flysheet and the groundsheet, and the floor figure is the one that decides a night on wet ground. Read the pitch type, because a shelter that needs pegs is worth less than its specification on the ground you have. Read the denier and the pole material, since fibreglass poles are where the cheap end of the shelf gives itself away.

The middle share: the bag, bought on a named standard

The sleeping bag takes the next share, and the money buys two separable things.

The first is a comfort figure you can trust to be comparable. Bags tested to EN 13537 or ISO 23537 publish comfort and limit values from a heated mannequin in a laboratory: an indication for lining bags up against each other, not a promise about a night, with the maker’s guidance governing use. A bag quoting a bare number and naming no standard cannot be compared with one that names it, and the difference is not in your favour.

The second is weight and packed size for a given warmth, which is what fill power and fill weight together describe. This is the classic place where more money buys fewer grams rather than more function — worth a lot on foot, worth very little from a boot.

Small money, disproportionate effect

A short list of items where a modest amount changes the experience more than a large amount changes anything above:

• Tent pegs. Tents ship with the cheapest the maker can supply. A set of Y-stakes in 7075 aluminium plus four steel nail pegs for the corners covers far more pitches than eighteen identical pegs.
• A long-handled spoon, roughly 20 cm, if you eat from foil pouches. A standard 16 cm one puts your knuckles in the food.
• A closed-cell foam mat to go under an inflatable one, which adds R-value, never punctures, and doubles as a seat.
• A repair kit matched to what you own — a splint sized to your pole’s outer diameter, and tape for your flysheet’s coating, silicone or polyurethane, since the two are not interchangeable.
• A head torch with a lock mode, so it does not run itself flat in the bag.

Where more money buys weight rather than performance

Past a point, the premium on almost every category in this niche is paid in grams and packed size: titanium instead of aluminium cookware, a lighter denier instead of a heavier one, carbon poles instead of alloy. Each of those is a real trade with a real cost on the other side — titanium heats unevenly and scorches, light denier scuffs, carbon fails suddenly where aluminium bends and can often be straightened.

None of that is a reason not to pay it. It is a reason to pay it deliberately, on the items you carry furthest, rather than across the whole list.

The running costs nobody budgets for

A kit is not a single purchase, and the second-year cost is where the arithmetic often turns out differently from expected:

• Filter cartridges, sold with a rated capacity in litres. Divide the price by the litres rather than comparing headline prices, and remember that storage and freezing end cartridges early.
• Gas canisters, bought by net gas weight — commonly 100, 230 and 450 g — and constrained by what the shops on your route stock.
• Consumable fittings: basket tips on trekking poles, shock cord in tent poles, gaskets in flasks and camping toilets, replacement seals generally. A flask usually outlives its first gasket, and it is worth knowing whether the maker sells one.
• Batteries or cells for lamps. A sealed lithium-ion pack makes a lamp lighter and eventually makes it disposable; replaceable cells cost more over time and can be bought in a village shop.

Where a maker sells spare parts at all is a genuine buying signal, and it costs nothing to check before ordering.

Buy in two rounds, a season apart

Buy the shelter, mat, bag and a way of boiling water. Go out. Then write the second list.

The second list is reliably better than anything you could have written beforehand, because it is made of the three things that annoyed you rather than the three things that photographed well. Chairs, tables, lanterns, showers, cool boxes and storage boxes all belong in that round, when you know whether you go out three times a year or thirty.

What not to buy on a photograph

Anything whose fit is a dimension. A footprint has to be smaller than the tent floor. A cartridge fits the housings its maker lists and generally does not seal in another. A canister valve is threaded, bayonet or pierceable and the wrong one will not go on. A pole splint has to slide over a specific outer diameter.

Those are not judgement calls and no amount of budget rescues them. Take the measurement, then spend.