Absolutely -- 18 months' experience is still very much entry level. Even if it were not, you still need a sponsor and that is where the plan very much falls down.
In order to sponsor you, a company has to meet one of the four following criteria:
the job has an annual salary of £150,000 or more; or
the job is on the shortage occupation list; or
your sponsor has completed a resident labour market test (or an exemption applies); or
if you are already here under Tier 2 (General) and you are applying extend your stay, you will working for the same sponsor in the same job.
IT positions at your level do not pay £150,000 or more (you'll be lucky to meet the £20,000 mark you need for the salary requirement).
They are not on the shortage list.
There are many IT specialists in the UK and even more in the EU, so it would be impossible to meet the labour market test and there is no exemption possible.
And you are not already here.
International student fees are anywhere from four to twenty-five thousand pounds a year according to the UK education council, so it depends on where you go to school. Based on anecdotes, the average I see is around ten thousand pounds per year.