What possible mechanism do subsidies have to drive costs?
You start overcharging because of the subsidy - all one of your competitors has to do is keep charging a fair price and they'll drive you out of business. Widespread collusion between small businesses is actually fairly uncommon - that's more megacorp territory, where the precautions and lawyers to avoid getting caught are a tiny marginal cost of doing business, and it's incredibly rare that anyone "who matters" ever goes to jail.
What they may do is largely eliminate the bottom of the market - if a $3000 system is the minimum that qualifies for a subsidy, then there will be dramatically less demand for $2000 systems. Who is going to want to pay for a $2000 system completely out of pocket, when a $3000 system is far more capable and only costs $1500 after the subsidy?
There may still be some niche demand for sub-$1000 systems, but generally speaking subsidy minimums are set with an eye towards the minimum widely useful system. E.g. few people will actually be satisfied by a smaller system for general use, and the subsidies aren't intended for upgrading for your hunting cabin that doesn't need more capacity..