How much will cost something like this site?

[panzerkampf39]

http://ipchecking.com/

How much costs coding something like this (with unique design and 100% SEO optimized)?

 

[DOPE]

Maybe this will help?
http://www.geobytes.com/

Sorry if it's not what you need, just what I came across.

 

[Loonycgb2]

It wont even cost 5$ you can find all the scripts online and make them work together as one script...

Its all ip and dns query scripts.

 

[VictoriaD]

Yes Loonycgb2 is right. But I would say for a 100% unique design you can count a bit more on that. Designs are expensive, if you want a good one. You can always do it yourself !