I know it's not really a work around like you seem to be looking for, but if you're doing enough $ sales on ebay for it to fit your budget, you could just get an older ebay account from someone. An older account would give you a bit more room to maneuver in terms of payment options.
If that's not an option, maybe you could structure your listings differently. I found that switching some of my auctions to "BIN "or best offer", works very well for discussing alternative terms with potential buyers. Whenever a buyer approaches me with an offer, I give them 2 options...a normal price, and a lower, more attractive price if the sale is handled outside of ebay. More than 1/2 of the people who end up buying things after using the "submit offer" choice, end up buying from me outside of ebay.
If neither of those really suits you, you could try to include additional checkout instructions into your item descriptions using html images. If you just write it in, it'll probably get picked up as they scan the page for potential rule violations, but if you write out how you'd like people to pay (i.e. "wait for invoice"....contact me prior to bidding", etc.), then save it as a .jpg or something, and add that "picture" to each of your listings, it won't be as easy for ebay to find. That might not help much if your account has already been flagged and is under scrutiny, but it's worked for me in the past to stay under the radar a bit.
good luck =)
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