Does anyone have any experience booking round-the-world tickets through Airtreks.com? Is that a good way to do it, or would y'all suggest another method?

Specifically, I'm looking to book 4 or 5 cities in Europe and Tel Aviv and Istanbul (I'm not sure what continent these are considered to be in). Airtrek's website is quoting a price around $2100.

Thanks,
reroute