There is a 35mm
portable projector forum out there that has many threads discussing this..I recently acquired a very small TOKIWA 35mm sound portable that is roughly the size of an RCA 400 16mm projector..I am just working on modifying the lamp and the reel arms before actually putting it into
mini projectors use..As for price, that is a good question as it seems to me that 35mm is by far the most variable in terms of price on both equipment and films...Everywhere from shockingly low to
mini projector very expensive..For estimate I would expect to pay anywhere from $250-$2000 depending on the type and condition of the equipment.