Let's start with some math. If you are paying $45 each, and you will print 30 1350 is your "break-even" point.
Define your quality, probably a 4 ink printer will not be good enough, so you probably need a 6 ink print.
Research how much each cartridge lasts, and the cost per print. Some can be refilled with a bottle of ink.
Define the cost of each roll of paper.
My advice would be for you to visit some "expo" about advertising, or promotional stuff, or printers or graphic arts or something near your city.
Look for brands like Epson, HP, Canon that have small plotters. Other brands have also "professional-grade" printers, more durable, like Roland.
Think of this as a one payment purchase, do not buy this on a credit or something, because normally big printing machines are intended to be as a business and that is not your case. You want to enjoy your prints, not suffer about payments.
Some con can be that if for some reason your gear starts to fail, for example, have one nozzle not working properly, all your prints will suffer from it. Some banding or whatever.
That will not happen if you keep buying your prints, you will get the maximum quality all the time if you have a good provider.
If you come to the conclusion that you do not want to risk getting a big printer, enjoy your current method purchasing your prints.
One option is that you buy a more modest size printer, like a tabloid and getting used to it, then making a leap.
Keep in mind that an inkjet printer must be working continuously so it stays in good shape. Not using it for a couple of days could mean that the nozzles can be blocked.
To keep them working you could talk to some friends and sell them prints... who knows.