I think growing your natural hair out would be the less expensive if you don’t get a style that requires maintenance every other week and you let it be its natural color. And has been said, you can lean to color and style your hair at home and save money.
I am lucky that I still have decent hair and have let it grow out to between my shoulder blades. I wish it were thicker but it makes a nice bushy ponytail which I wear in public. At my age I know I probably only have four or five more years before I’ll have to cut it so I enjoy it while I can. I’ve considered using hair growth products to prolong that time… idk. I don’t color it so its a natural silver/white which the wife likes and she trims it for me so no salon expense at all.
I used to wear synthetic wigs and still have several. Some are short and some are below my shoulders. They were always hot, easily tangled or frizzy, and did not stay put very well with activity. The benefit of wigs is you can easily change styles and colors.