personally I have a load of s9's sitting in hosting complexes, much better roi with added benefit if no import duties!
just some things to think about
+1 to that!
I have 1 Avalon 741 in the house which does a damn good job at keeping it warm in the winter. Come the summer time i will take it outside.
At 1150W it costs around £3-£4.40 per day, depending on your rates. My day rates are 16p per kwh, and night rates i dont know. my best guess is it costs ~£3 per day to run. Per THs you earn ~ $1.5 per day. Profit wise that is ~£4/day for me. I also consider that i have not turned the central heating on, and that probably saves £1-2 per day. I have just changed energy provider and i will start paying less for electricity - have you switched recently and got a good deal on electricity?
Like squall says - for any future purchases i will have them hosted so that i dont get hammered by the import VAT and duties. Additionally, i am happy with just 1 miner kept in house.