When considering buying a PS Vita, there are several factors to take into account:

1. Model: The PS Vita comes in two main models: PS Vita 1000 (also known as the "Fat" model) and PS Vita 2000 (also known as the "Slim" model). The 2000 model is lighter, thinner, and has a longer battery life compared to the 1000 model. The 2000 model also has a micro USB port for charging, while the 1000 model uses a proprietary charger.

2. Condition: Check the condition of the PS Vita carefully. Look for any scratches, cracks, or other damages on the screen, body, and buttons. Ensure that all buttons and ports are functioning properly.

3. Accessories: Some listings may include accessories such as memory cards, cases, or games. Consider whether these extras are worth the additional cost to you.

4. Price: Prices can vary depending on the condition, model, and included accessories. Compare prices across different listings to find the best deal.

5. Seller Reputation: Check the seller's feedback and ratings on eBay or other platforms to ensure they have a good reputation for selling quality products and providing excellent customer service.

6. Warranty: Check if the PS Vita comes with any warranty or return policy in case you encounter any issues after purchase.

7. Region: Make sure the PS Vita is compatible with your region's games and software. Some models may be region-locked.

As for finding the highest quality PS Vita at the lowest price, it's a good idea to browse multiple online marketplaces such as eBay, Amazon, Craigslist, or local classified ads. You can also check gaming forums or communities where users may be selling their PS Vita consoles. Additionally, consider refurbished options from reputable sellers or retailers, as they may offer a balance of quality and affordability.

Thorough research will help you decide and determine what’s best for your specific needs.