I'd like to offer some helpful tips from a professional to anyone needing to replace your water heater.
First, if you're wanting to do the installation yourself, don't buy a heater from a big box store. They are less expensive because they are lower quality. Significantly lower quality.
The steel is thinner and lower quality, they are less efficient , have plastic drain valves instead of brass, and smaller anode rods made of aluminum, not magnesium.
If you're investing your time installing it yourself, buy the best heater you can afford. My recommendation is Bradford White. Their 6 year warranty water heater is great. There's no need to pay extra for the 9 or 12 year warranty. The major difference is larger or additional anode rods. If you can install a water heater yourself, you can replace the anode rod every couple years.
If you decide to have it installed, use a licensed professional. There are a lot of things you can hire a handyman (or handyma'am) for. Plumbing, electrical, and HVAC aren't on the that list of things (unless you've known your handyman a while and they're great).
Be aware most companies won't give a price over the phone. Plumbing companies compete for water heater installations. Only giving in-person pricing means they already have a foot in the door, literally. Most people will not send someone away once they are already in your home ready to do the job. The company is counting on it.
There ARE companies who will give prices over the phone. They will likely ask several questions to get the details correct. Being patient with all the questions can save you money.
Most importantly use a company that's been around a while and have a good reputation. It's estimated than as many as 85% of plumbing companies fail within 5 years. If there is a problem down the road, you'll want them to come take care of it. After all, that's why you hired a professional.
If you have any questions, I'd be happy to answer.