Only 4GB? Even 3GB 1060 cards are still capable of mining Ethereum, and they're usually most profitable mining ETH, with the runner-up being Equihash. The 1050tis aren't as profitable currently on Ethereum compared to Zcash, but they sure are capable of mining ETH.
The 1050 Tis make around $25 per month on Zcash currently according to Nicehash and some other calculators I used, so assuming you get one for the price of $200 you break even in around 8 months with no changes to profitability (which will fluctuate, of course). I've noticed recently even the 1050tis have gone up in price, I recall seeing them sell for near or below $150 just a week or two ago and now they've climbed to $200 on Newegg.
The R9 series was profitable with mining for about as long as I can remember being in Crypto mining, and it still is. Past performance doesn't indicate future performance, though, especially with mining. Nobody knows if the 1050ti will be profitable even a year from now.
I agree all the way, 4GB really isn't trivial. Especially when you can just stack multiple of them and make it virtually any amount you would like. 8-months is a bit long for ROI in my opinion, but that's definitely not that bad for the price point at all. Ethereum is remarkably easy to mine on, compared to
BTC GPUs are actually still viable. The price climb is probably because people are going down their list of GPUs they'd like and as stores sell out they move on to a new card to sell out. I would expect the 1050's to climb until they're $300+ or sold out. The R9's have been absurd in their longevity, but I'm hoping the 1080ti's have a longer run.
I would never recommend those low end cards to any of my customers. Now is not a good time to try and build any GPU rigs, doubly so if you are targeting these near useless low end cards.
Why wouldn't you recommend them? The lower end cards are very profitable in certain instances, plus what if their budget is lower? I have heard endless success stories with low end cards and it would be foolish to discredit these. I also disagree that now is a bad time to throw together a GPU rig, if you can find good prices on a couple cards you will be rewarded handsomely as always.