It's 180 days. Not 6 calendar months. Would it have been 6 calendar months then the stamp would have said July 28th because both start date and end date are inclusive. So you only "lose" 1 day.
Yes. It varies with different embassies but the RRP is 10 000 THB... Some embassies charge more just because they can... (and maybe to get some extra in their pockets)
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