The problem is that is not how paypal handles things. That seller has been around long enough and "sold" other welders. Paypal may have locked things down due to volume at a certain point, but they definitely got a ton of money before that happened. Paypal says they can hold it for 21 days if they think it is needed and volume of sales is the only reason this seller would fit.
From Paypal's website:
Payment delays typically affect new sellers or sellers in categories that have a higher than average rate of refunds, disputes, or chargebacks.
In deciding whether to hold payments in a pending balance, we review many factors. These factors include transaction activity, the rate of customer disputes, the type of business, average delivery time, customer satisfaction, and history. We understand that some experienced sellers may be affected. While history with PayPal is important, it's only one of many factors we consider.
Here are some common reasons we may hold payments in a pending balance:
You have limited history or selling activity.
You have low Detailed Seller Ratings, negative Feedback, or other indication of below-
standard performance on eBay.
You have a high rate of customer refunds, disputes, claims, or chargebacks.
You're selling in a high risk category or industry such as tickets, travel, gift certificates, computers, consumer electronics, or mobile phones.
Your business or selling activity is inconsistent. For example, you have a spike in selling activity, your average selling price changes, or you started selling in a new category.
The account information you have provided is incomplete or inaccurate, or we're uncertain about the information you've provided.
Your withdrawal activity has changed.