Commission costs when trading futures.

Interesting, how much is it advisable to lay on commissions when testing American futures and, так называемое, slippage. Sometimes I meet an opinion, what if liquid ES futures are traded, then it is enough just to lay the commission 2 доллара на контракт. Maybe, mean that slippage on such a liquid futures makes no sense.
Хм-м-м ….But the thing is, what when testing, usually, no bid and ask, which are in real trade, there are only prices on the test, on which transactions took place. And the difference between bid and ask is always, least, at least one tick — for ES it is 12,5 Dollars, actually. Сомневаюсь, that a trader will always be able to buy at a bid and sell at an ask — rather the opposite.
If the trader's counterarguments are that he only trades limit orders, then in this case those, the fattest" deals on tests, which opened only by touching a limit order and immediately reversed, let's go in the right direction, in real life will often not be performed, but those, which went right through and got a stop loss, in real life will always be performed. Therefore, the use of limit orders on tests sometimes, or rather, even always, lead to too optimistic results.
But okay, отвлеклись — it's not about limit orders. So how much to pledge costs in tests on American futures? In particular, for ES, I would, would not hesitate to lay 12,5 at the entrance, 12,5 to the exit, well, plus the broker's commission, for example 5 dollars per circle per contract. Total 30 dollars per transaction. And this, least.

At all , I have looked a lot of different commercial systems, or rather their tests. And somehow authors and independent experts, practically, are unanimous in their opinion and lay down costs approximately in the range of 25 to 75 dollars per circle. But these are modern, relatively new system builders. And if you dig deeper — 90-e years and the beginning of our century, then the standard was from about 75 to 150 dollars per circle.
In particular, independent firm, testing and comparing all kinds of systems for the futures market, FuturesTruthMagazine applies the following slip standards:

Commission/slippage used: $200/rt for ND, $100/rt for SP, $25/rt for e-minis, $75 for all other markets.

Who disagree? In particular, I would like to hear the opinion of the respected osmar92, since he trades fairly short-term trades in these futures — whether such costs are too critical for frequent intraday trades?

Why do I ask — just came up with a short-term system yesterday on a futures portfolio — the profit line goes up exactly, like a ruler, but the profit per trade is small — Total 98 долларов на контракт…. And the test was without taking into account commissions and slippage :)