West Hartford does have a reasonable selection of multi-family homes. They are mostly two and three-family homes and usually located in the southern and eastern portion of the town. They are regularly available for less than $300k, though homes in good condition and closer to West Hartford Center can go for much more.
Currently, the market for these sorts of properties favors sellers. The number available has fallen over the past few years, so demand from buyers is out of balance with supply from sellers. It is not uncommon to see multi-families listed and then quickly go under contract as multiple investor buyers bid against each other.
Rental rates in West Hartford are generally stronger than in surrounding towns, though they obviously depend on the particulars of the unit ... location, condition, size. Most multi-family homes are made up of 2+ bedroom apartments that are 1,000+ sqft and can easily bring in more than $1,000 per month. CraigsList dominates the rental scene here, so check that out for a better sense of how much rent you could command.
Mill Rates are a good place to start when comparing taxes between towns, but there are other factors involved too. West Hartford has a higher mill rate than other towns, at 38.38 ($38.38 in tax per $1,000 in assessed value). As you look through listings online, be aware that the property taxes are often incorrect. West Hartford did a phase-in during their most recent revaluation in 2006 but then froze it part of the way through. So our local MLS actually calculates the taxes wrong and not all agents correct them. There's a page on the Town of West Hartford website (West Hartford Tax Estimator) where you can confirm values.
Finally, the single family market in West Hartford overall has trended in line with the overall County (http://www.amybergquist.com/blog/2011/01/17/our-2011-predictions/
). One exception is the West Hartford Center area, which was very strong in 2010, definitely a seller's market. You can find homes in town at all price points from the mid $100s through the millions. You should have a nice selection of property styles and locations with a $300k budget - it's all about what you like in an area. The most common type of houses in town at that price point are 3 bed, 1.5 bath colonials at about 1,500 sqft, in a 1940s to 1950s vintage, but there is a nice variety.
$300k will generally get you a little more house in some of the surrounding towns. And other towns do have more active, and more favorable to buyers, markets in multi-families. There is a wide variety of possibilities in Greater Hartford. Hope this helps.