[ainarssems]

Well my RX480 purchase was a bust. After searching far and wide for new RX480 at good price that was in stock I thought I got lucky find one. Unfortunately next day got e-mail saying it's out of stock with ETA 4-5 weeks so I cancelled and bought a second hand from e-bay paying more than for a new in the first place. Well actually bought 2 as the math show good investment and even if in unlikely event it does not turn out that good the second hand prices are high due to demand and no stock often exceeding new prices when new were available. The replacement RX580 which is also not available seems to be better in games but worse for mining and using more power. GTX 1080 TI is a lot more expensive and takes longer to pay back, but will generate more money after it's paid off. From what I have understood AMD cards are more flexible in terms of mining different currencies and different algorithms so you have more options to switch to if some currencies became non profitable to mine but I am sure if all of the ones you can mine with nVidia cards became unprofitable somebody would make new algorithms to use them, but it seems AMD cards are a safer bet with RX480 8GB being the best at the moment.
Short term crypto currency value can go up and down but over long term most of them have increased a lot in value. Obviously there is no guarantee that it will continue that way but if you look at the trends it should continue to increase in value. There are short term value fluctuations and you could make fair amount of money if you guess it right or were lucky buying and selling at the right time but the best idea seems to put your spare money into getting crypto currencies and keep hold of them. You can make more money trading with leverage but also loose more and if value drops suddenly and you do not have extra funds available to prop it upp you could loose everything you invested if trading with leverage, also cryptocurrencies are traded 24/7 unlike shares in London exchange for example 08:00-16:30 on work days so you can miss price hikes or drops while you are sleeping.

There are lots of different crypto currencies and I am doubtful there is enough market space for all them long term so there is a bit of risk deciding which ones you want to invest in to.

also tried to mine Ether directly it turns out you need at least 3GB GPU memory so at the moment I could not even try with my GTX760 2GB while waiting for RX480 to arrive.

Also looked into power supplies, if you are to run 4-6 GPU's you will need 1000- 1800W PSU depending on GPU model and quantity and those are very expensive, for me it seems to be a lot smarter to run 2x650W PSU's that will be less than £150 instead of single £300 1300W PSU. Then I looked even further and decided that it might be even better getting second hand server PSU's for GPU's. As they are made for servers they are made to run 24/7 and with reliability in mind and sometimes can be had for peanuts on ebay, only downside is that mostly they are a bit loud. You can get 750W PSU that gives over 60A on 12V line for less than £40 on BuyitNow and less on auctions.