I don't know how mechanically inclined you are but a hot water heater replacement is a relatively easy install. The hardest part is carting the old unit out. The sludge build up inside makes old units HEAVY. When I replace mine, I buy a new unit with similar hook up locations to make the job basically a plug and play without extensive adapter modifications.
If the scale tips into the hire rather than do it yourself balance, a plumber should be able to do this job fairly economically. You can price units at Lowes, Home Depot, Sam's, etc. to get an idea how much the units cost. I'd guess labor should be around $100-$150. Not a plumber so my numbers may be off.
Edit: Richmond is made by Rheem, I believe. Here's a 50 gal. Rheem from Amazon for $470 with free shipping. I'm not saying do it yourself, just offering a price on a similar unit so you can annoy any plumbers.
http://www.amazon.com/dp/B001F9UW62/?tag=tcg21-20