Downloading the CD version of the program from anywhere other than an authorized reseller of Intuit products is risky at best. The list of authorized resellers is quite a bit, and in my neck of the woods are all well known. For example, Wal-Mart, Amazon, Frey's, Newegg, and a number of others.
Now those were authorized resellers last year. Doesn't mean they will all be authorized for 2018. I'll have to ask if a list exists yet, but I know that nobody will get back to me until Monday at the earliest, since TurboTax Support is closed on the weekends.
The website you mention (taxpros19) sounds more like a fly-by-night setup that will be gone as fast as it appeared on the web. So I'd definitely avoid it.
Now the surest place to purchase the CD online (other than physically going to your local retailer) is at https://turbotax.intuit.com/personal-taxes/cd-download/
