I rarely bid if their feedback isn't 100% positive.
This is the type of buyer, sellers such as myself pray do bypass our stuff altogether. 100% positive? Cmon...be realistic.
I sell under 2 ebay user-ids -- and have gotten negatives from arseholes because
* stuff wasn't sent the day after they paid (even though we clearly state posting is done once a week)
* they can't read properly -- stuff is aptly described and photos provided -- yet when in the description it says "some wear" they somehow think this should mean that you have to supply them a brand spanking new product
* they don't pay -- so you give them negative -- and they retaliate with one
* there are kids who get their kicks by buying a heap of stuff only to leave negatives 30 seconds after the end of the auction/listing
* etc, etc, etc
Finding a long-term seller on ebay with 100% is going to be damned near impossible.
What you need to look at is their feedback percentage. Anything less than 100% I always check to see what caused them to lose that 100%, and how long ago. I have bought high valued stuff from a low-volume seller with a percentage of 85% in the past -- the one negative he received 2+ years ago from a retaliatory buyer is what caused that.
If it is aircraft models you are buying -- and the seller has these details:
1150 Walnut Glen CT
United States 95926
or the name of Monte Wibble or resides anywhere in the Chico, CA
area -- run as far as you can -- 12 months down the track and I am still arguing with ebay about getting the money they claim to cover me with under their buyer protection program.