It was just easier for us when buying our Condo last week to use an agent. Also 1250 Bahts from that amount is deposited in your account so no big deal.
We will apply for our Non O Retirement Visas when we arrive in December, cheaper than doing it here.
It does take time for money to show up in your bank account, it took 4 working days for us when transferring a large amount from the UK. Think it went via Kasikorn bank before it arrived in our Bangkok bank accounts.