They're being pragmatic, they actually want to get paid, and they don't want the US to have to pay for all of these weapons and other material. Not everyone you disagree with is a Russian asset, no matter how hard that narrative is pushed.

All of the "aid" the US has sent to Ukraine has been on credit, a 21st Century lend-lease. The original 20th century lend-lease was a roaring success in terms of subjugating the British empire, and it's also worth noting that a lot of US representatives of that era were very hesitant to approve the "care packages" in the first place as well. The debt Britain owes the US from WWII has actually never been repaid, but the US got global hegemony out of the deal so they agreed to look the other way.

Ukraine however has no ability to pay off the debt they have already racked up, let alone more. Not just because they've lost militarily but also because anything remotely productive in the country (primary farmland and factories) has been parceled off to the highest (US based) bidder, destroyed via the war, or can't be productive in the foreseeable due to the loss of working people to emigration and war.