> 4 - Buy and colocate the hardware yourself – Certainly the cheapest option if you have the skills, scale, cap-ex, and if you plan to run the servers for at least 3-5 years.
Is it still the cheapest after you take into account that skills, scale, cap-ex and long term lock-in also have opportunity costs?
Personal experience: Did some cloud stuff for SME, and later on started colocation. I think my learning curve for all the cloud-stuff was the same as for all the colocation stuff, except the cloud will not get you rid of firewalls, NAT, DHCP and all that stuff. Cloud isn't that much easier, it's just a little bit different. IMHO, the largest disadvantage of colocation is that it requires (sometimes) physical presence at a datacenter.
Is it still the cheapest after you take into account that skills, scale, cap-ex and long term lock-in also have opportunity costs?