Is it wise to buy some text links on high PR Web sites?
Definetely not. I would never purchase a link on someone elses Web site. I advise against buying text links. There are many people who end up paying money for what they think is a “valuable link” never realizing that there are plenty of scams out there that, look like link, behave like a link but are in fact of zero value.
It’s better to focus on building quality links (build them for your visitors) and avoid all manipulations.
If you have a budget to spend money, why not apply it to something that is legitimate Pay Per Click (PPC.) PPC is paid advertising and it can be very complimentary to your SEO work, as long as you monitor your results.