IMHO the price does not matter as long as its reasonable for the niche. The design looks good, but its by far not the only thing I would look at before buying. Out of the head... these things interest me in addition to good design:
- Speed - if the theme slows my browser due to excessive JavaScript (and I see a lot of these nowadays) its a big no
- Speed - if it scores less than 90 here
https://developers.google.com/speed/pagespeed/insights/ I'll never buy it
- Generic approach - I would generally attempt to buy a theme that can be turned into corporate/affiliate/blog/e-commerce website
- Mobile ready - if the user has to use a zoom function on his mobile phone its another big no
- Social networks ready - Open Graph, twitter cards are a must
- Blog section generally interest me most, because it is the one that attracts traffic from Google.