If you have $8 a month for fun, maybe not. If you have $8,000, sure it's worth the money. No one but you can answer the question you asked.
You've done the research and made your pick, so now you have to take a risk. If it was me, I'd be open and say that I wasn't sure about a BS, because it would be my first, so let's start w/ NR (or even N). That way, you aren't stuck if no chemistry starts to perk. But make it clear there's an upgrade on your mind and in her future if it does.
'Nother thought: chemistry/good times usually improve w/ repeat visits. If it's a lot of money to you, maybe you'd be safer spending it on someone you've already got a rapport with. Or after you've had an intro session w/ Mya.