Before spending money on commercially prepared products, try performing the room adjustments using conventional, room friendly (WAF) products.
Rugs, carpets, throw pillows, overstuffed furniture and bookcases loaded with books, are great for absorbing and diffusing sound problems.
Versus a local vendor, online vendors are going to just supply a "product" were as the local vendor is providing "product and service".
If you truly need commercially prepared room treatments, you really need the services as well.
PS: I do not work in the audio industry.
