Many people on the forum are so quick to recommend spending $$$$ on a new Mac just because a Mac is older.
I think if the Mac is generally adequate for the task, but could be improved by investing a (relatively) small amount of money, why spend thousands now, when you can spend a fraction of that and have a similar experience.
But, is it even with it given that it’s a 7 year old desk top computer?
It totally depends on what you plan on doing with it.
It’s used for email and web surfing.
If that is it, then those upgrades would totally be worth it.
Just make sure you know what you are getting into. It really isn't that big of a deal, and people act like it is rocket surgery, but you can damage the display and connectors if not done correctly.
Use the right tools, especially the pizza cutter-like tool, and know where to cut.
Get someone to help you when disconnecting the cable connectors, especially since you first time.
Use quality adhesive strips, and clean old strips really, really well. When putting back together, clamp with your hands or some tape for a while to make sure there is good adhesion, as some report that the display fell off a few weeks after. I am sure they didn't clean well, use quality strips (or they went bad), or give enough time squeezing it to make sure it was together.
I can upgrade the RAM and change out the spinning hard drive with an SSD for about $300.
What size SSD where you looking to get?
If you want to save yourself the trouble of opening your Mac, maybe consider using a USB or TB drive.
If it is SATA, it won't be as fast as an internal SSD swap, but it is quick, easy and could be about as cheap as doing an internal drive. while the speeds wouldn't be as fast, they would be faster than your HDD, and much more responsive.
You can get a 1TB SATA SSD and a USB3/SATA adapter for less than $90. You can always decide later to install it internally if you want a cleaner set up or faster drive.