As long as the damage is not extensive, I’d probably go for the weld repair. Oil pans don’t have much stress on them. To get a good weld they’ have to completely remove the pan and clean it thoroughly before doing the welding. As long as they do it that way, for a $200 savings over a used one, I’d go with the weld.
I should note that holding to a frugal nature, if I had the problem myself, I’d put on some old clothes, with some grease spots, a SF Giants baseball hat, I’d drive down to the local auto recycler yard in my 40 year old truck, laugh at their jokes (junk yard jokes not as good as plumbers jokes, but still pretty good), maybe share a cup of coffee and chit-chat, agree with whatever political views they hold, then after a while I’d tell them what I’m looking for, that I’ll pay in cash, need no receipt, and ask them what all they had in stock in the way of used oil pans. I’d offer to remove the used pan from the junked car myself if necessary. I’d be surprised if they asked more than $100.