If you going to spend money please get a blue ray player, dvd players are on the way out, i own a video shop and im putting more n more into blue ray, i have over 1000 bd, and about 17-18000 dvd, alot movies i cant get on bd so why get rid of the dvd,
when it comes buy new movies i but a min of 30% bd, and upto 50% + (hobbit will be 52% BD)
Any shop that dosent keep there stock clean wont last very long, i have 2 machines and spend over 1k a month of polish for them (tbh i think thats bad coz it means all my stuff is getting scratched)
as for the physical difference between a dvd n bd 50% thinner disc and 8-10x better image and sound after a month of watching bd you wont want to watch a dvd ever again
just remember to plug your bd player into ya internet (wifi or cable) and keep the firmware up to date
Hope that helps