Debit cards work the same way as credit cards with PayPal. You can't take them without getting charged. Instant transfer and e-check are basically the same thing. Instant transfer can be used by people who have a credit card on file, but the money comes from their checking account. If they don't have a CC on file, they do an e-check, which takes a few days to clear. Instant transfers clear immediately.
As for telling them how to pay through PayPal, I ALWAYS send winning bidder e-mails and ask my customers not to use checkout. Most usually do checkout anyway, but it doesn't do them a whole lot of good. Below is a generic copy of the winning bidder e-mail I use, which outlines all my payment options.
"Congratulations on winning the above mentioned auction! Your winning bid was $xxx and shipping is $xxx. Your total is $xxx. You may pay via PayPal (funded accounts, instant transfer or e-checks ONLY!!, no debit or credit cards). If you prefer to use a debit or credit card, you may pay via
www.c2it.com. They will charge you a 2% transaction fee w/ a 30 cent min. (often less than a money order and stamp!!). There is no other charge. The $10 mentioned on the site is for international transfers. Payment address for both of these services is xxxxxxxxxxxxxxx. I prefer to be paid via one of the above methods. However, you may also send a money order, cashier's check, or well-concealed cash to
Mary xxxxxxxxx PO Box xxxxxx. xxxxxxxxxxxxx
I ship on Tues. and Fri. I will leave positve feedback upon receipt of your payment and ask that you do the same for me upon receipt of your merchandise.
Please let me know within 3 days how you plan to pay. Payment not received after 10 days will result in filing of non-paying bidder report, negative feedback and possible E-bay suspension. Also, a reminder, no personal checks.
Thank you for your purchase. Mary"