I watched used ASIC miners in eBay for about a month and waited to find one at auction at a good price point. I got a good deal on an A4 Dominator which I attribute to a combo of a short acution window and a lull in the price of LTC.
My recommendation would be to wait patiently for a great deal at auction. Resistant the temptation to over pay, fight your LTC mining FOMO.
I think it’s safe to say others will recommend waiting to buy a miner and investing the money you would have used to buy a rig in LTC for the time being.
I have cash on hand that I’m keeping in LTC and VTC and I’m watching miners on eBay. Once I find a good one at the right price, I’ll bid and buy with my credit card, then cash out enough L/VTC to pay the CC bill IN FULL when it comes due.
I would not recommend wasting money on a mining rig that isn’t best of breed (or close to) because the difficulty will rise too fast and you’ll never see profit. When I do my ROI calculation, I factor in that I’m going to resell the rig on eBay. If you buy best of breed, it will probably (hopefully) have some resell value. Older miners can’t really be resold since they just waste electricity.
I don’t recommend building your own.