If you pay in Bitcoin instead of eth, you can post it on the services board.
However, I recommend changing your requirement: asking for DT only to join looks a lot like you're buying trust. You should ask for trusted members instead.
A lot of users do this, but they tend to disguise it by giving free credit in "tiers". So they give trusted members more, and other users lower. In principle its the same thing they are looking to get reviews from trusted members by offering an incentive. Quite frankly, I would be more inclined to trust a project if they went a more ethical approach, but each to their own I guess.