I'd advise you to check multiple tires/rims shops before you buy from any particular place.
If the EuroStar tires on your 2011 model XLi are in somewhat good condition, they can easily fetch anywhere around Rs. 13,000 or maybe more. The steel wheels and hub-caps should be worth at least Rs. 6,000 (not sure about the latter though).
As far as the rims' country of origin is concerned almost all of the stuff that is available in Pakistan is manufactured in China and then stamped with "Made in Taiwan"/HK, Korea, Malaysia, etc, as per the wishes of the importer/distributor. So take the tire/rim-vendor's advice with a pinch of salt. Bring a friend or two with you and examine the rims you are interested in, looking for any imperfections that might exacerbate with usage. 15" or 16" rim size is, frankly, your personal preference. But I would personally not exceed 15" rim size in a PDM Corolla -- else, there might be excessive wear on your suspension and EPS.
As far as tires as concerned, some of my friends have warned me time and again that a lot of games are going on in Pakistan where tires which are nearing the end of their stipulated shelf-life (let's say 4-5 years) have their expiry dates tampered with and resold as almost-manufactured-last-month tires. So be careful when buying tires and especially examine the markings/stamps on the sides of the tires and try and decode the manufacture/expiry dates of any tires you might be interested in.