I have been mining for the last few winters

[truckinusa44]

I would probably mine continuously if I had a place to keep the miners cool.  For the last 3 years I have bought a miner in the fall and sold it at the end of winter.  I basically use it for supplemental heat and a lottery ticket for solo mining.  What type of miner should I invest in?  I lean towards trying to obtain an S9.  Last winter I had a S7.  I sold it for almost the same price I paid.  I am aware that a number of alt coin miners are also available.  My goal is to lose as little as possible when I resell the miner in 4 months.  Where should I obtain the miner and what should I be considering?  I have been keeping my eye out for GPUs, but it doesn't seem like something that is easy to get.  I recently replaced the GPU on my PC and purchased a 1060 3gb model because the price is right.  Apparently it hashes at 15mh with my attempt at mining with it.  I need it to work for my PC so I don't care to mine with that full time.  The deal I got I was only able to get one for $175.  My electric rate in the winter time is 4-5 cents a KW/h.

[Aurel577]

That is cheap electric I pay about double that. I also like the free heat I get in the winter months coming from the miners in the basement.

[leowonderful]

Realistically speaking the S7 or any miner of that generation will no longer produce much at all even at the low electrical cost of 4-5c per kw. Difficulty is rising too fast as it is. I'd recommend an S9 at Bitmain prices or some Dash/Litecoin equipment if you are lucky enough to snag one at manufacturer prices.

I hope you are aware of the noise the S9 makes. It's about as loud or more loud than the S7 due to even higher chip density; if that's an issue, the R4 will work.

[QuintLeo]

Given you're using it as a heater replacement (effectively free electric), pretty much anything semi-recent should work. S7 again, S9, T9, R4, Avalon 741, etc.

 S9//T9 should be right at the same noise level of the S7 you used to have, the rest will be quieter.