If your goal is to save money with the original installation, small cans are not the most economical way to go. Lamps will cost more also. A standard 6" can works fine on a 10 ft. ceiling. A 6" can will give you the best variety of bulbs also. Small housings are always more expensive that 6". If you have a dealer in your area that stock 5" housings, the price may be comparable to 6".

Thanks for your reply ginger light! I know that there is much more variety in the 6" can selection and that would give me plenty of light, but my reason for wanting the 4" cans is to have smaller, less obtrusive holes in the ceiling. I am just wondering if, with the smaller size, and therefore 50watt bulbs, I will get enough light. As it is the bedroom I don't need super bright, task lighting, but I would like to see in my dresser drawers.

You should consider a 5" recessed fixture, using a 75Par30NFL lamp.
As your ceiling is 10' in height, you should keep in mind that the amount of light landing on your dresser drawers, or any other furniture, will be 50% less than if your ceiling was 8' high.
So to get the same light levels you must use a higher wattage lamp...therefore in a larger can

For stronger light with a small aperture fixture in an AIC housing your best choice is low voltage halogen fixtures since that's what they were designed to do.

Otherwise you can try one of the 3" Lightolier line-voltage LytePoints (basic adj. 385WHX baffle or adj. pinhole 308WWX so you can light the walls instead of the floor) in a 302 ESAICX housing with a 50 w. GU10/ES16 lamp. These aren't really much cheaper than a low voltage fixture and they put out less light.

Alternatively, in order to save a few dollars, try a 3 3/4" Lightolier line voltage LyteCaster non-adjustable step-baffle downlight (2005WH) in a 2000 AIC housing with a 50 w. PAR20 lamp. These are good if you own really nice oriental rugs but they don't do much for the walls.

You should be very careful when locating recessed lighting in a bedroom since that is the one place where you are most likely to be looking up into the fixtures. I don't know where a 6" recessed light would be appropriate in a residence but it's definitely not anywhere near a bed but I think you already know that.

Many recessed fixture brands have to reduce the allowed lamp size in order to meet the heat output limitation of an AIC housing. I have found Lightolier to be the best of the mid-priced fixtures in this regard. Halo is the worst. If you install one of the brands that do this, and then install a larger lamp, the fixture will eventually cycle on and off as it overheats and then cools so it's very important to pay attention to the lamping charts which are often found inside the fixtures as well as in the catalogs and the installation instructions.

Thank you all for your advice!
Sharon