Thanks, for suggestion, @tim. I will certainly look to cron.
Everyday visits lay as a burden to someone in a middle sized company. However, in the long run I'd figure out how to update info once in a while.
However, currency rate in that country is too unstable lately. And central bank publishes rates once a day only. So, i suppose, manual inputs will occur more often than a daily visit to update.
Edit: PS. You mentioned realtime, that's doable. But myself, i don't want to visit a shop with fluctuating prices. Especially if they change once an hour

PPS As a followup, a couch template is perfectly executed with a cron-job set in Cpanel. Data is fetched and persisted to database every 4 hours without issues.