My strategy is to buy bitcoin this year, then possibly invest in mining/general-purpose hardware to protect the network in about a year.
I plan on wasting about 12Watts on (intermittent laptop) mining this year (currently burning closer to 100 using desktop CPU mining).
By the end of the year, I may even investing in panels and batteries to run 12Watts exclusively from solar power
I guess my point is, you can choose how much you "waste" on mining with no expected return.
Note that my CPU miner strengthens the network, even if it never processes any blocks. With (currently) 70 connections, it relays transaction announcements and block history to other nodes.