umm, where are your REAL facts...

like:-
production cost (material cost per T)
running costs (rent, utilities, rates, staff wages)
projected turnover (how many will you sell - on month by month basis)
+
how much cash resources total do you have available
You need all these & more to draw up a proper cashflow forecast;
from this you can judge whether its worth going into business.
(Rule #1 with business... when you run out of cash, you get run out of business.)
Being where you are, have you considered where are you going to get
your raw materials supplied from? (eg shirts, vinyl, machine spares)
Are there any local suppliers or will you have to import everything too?
Machinery isn't cheap but is only a startup (oneoff, capitalised) cost.
Actual costs of making that shirt is what will hurt you in the long run
if you cannot control costs low enough to make a decent buck
selling at the pricepoint/s your market demands.