Here's my two cents worth:
1. Find out from your local amateur radio club (
ARRLWeb: ARRL Home Page) where the nearest repeaters are located....from your home, work, commute, school, etc. If you live underneath a popular repeater, or travel in sight of one, a portable radio will do fine.
2. Why not do both? Depending on which type repeater (e.g., VHF or UHF) is more prevalent in your area, you could buy both a VHF mobile and portable for about $300. I like Yaesu equipment, as they tend to have more channel storage and wider receive ranges (ok, not compared to every radio....but this is MY view over the last ten years).
3. With an amateur radio, what will you do? Chat on the daily commute? Participate in ARES, SKYWARN, RACES, etc.? Listen only, as you learn??? The answer to these questions may help you decide which type radio best fits your needs today....
A dual-band mobile and portable radio would be the ultimate collection, unless you don't have any UHF repeaters.....I've owned ICOM, Kenwood, and Motorola radios. Pick one that makes sense to you....visit your regional Ham Radio Outlet, Amateur Electronics Supply, or equivalent store to play with all the toys. Check out the dealers' booths at your neighborhood ham fest.
One smart way is to buy the same radio as others in your club/area. That way, you may have local experts to help you if you have a programming or operations question. Someone may have a used radio for sell..........
In my view of amateur radio, I use two mobile radios (one for APRS, one for scanning & monitoring 146.52 when commuting/traveling) and two portable radios (one UHF, one VHF) here in Jacksonville FL. On a good day, the UHF portable is the minimum required for keeping up with my fellow hams. On a busy ARES/SKYWARN day, you could potentially use all four radios.
Enjoy the hobby,