There will always be a significant difference between assigned indoor garage spot (mainly because of demand, maintenance overhead, security and protection from the weather); a covered outdoor spot which is less to maintain, easier to keep secure and also does not keep your car free from weather exposure.
Hope this helps.
The Schaffer Realty Group
Make sure you know if it is assigned or deeded too. Deeded you pay a seperate tax bill to the city (usually not much but it is a pain). You should be able to get a PIN number if its deeded but not if its assigned. When we market new developments, I always recommend assigned because it alleviates a ton of paperwork both for the builder and removes the hassles (and taxes) for the buyer.
Outdoor spot: $12,000-17,000
Could be more epsecially in some high rises. More details and we could give you a more accurate assessment.