If other homes in the area were similarly built you may not have a lot of trouble without a garage but if it is something unique to your house it might have more of an affect. Have you considered renting a large shed for the property? This could give the buyer the ability to feel like they have ample "storage space" while passing the option to continue renting it along to the buyer. It isn't a replacement for a garage but sometimes it can bridge the gap.
I am not sure what type of home or in what community you wish to know about however, just as an example: In Killearn Lakes the recent three months sales showed 4 homes around 1600 sq. ft., 3 bedroom 2 bath, no pool, built around 1989 and 1990 . Three with a one or two car garage sold for $104 - $109 per sq. ft. One with no garage or carport sold at $92 per sq. ft. Factors such as location and condition will cause these results to vary quite a bit. I hope this is a little helpful.