I have a personal reservation in Economy, in which I am offered to bid for an upgrade.

Does anyone have any information with regards to the recommended bidding amount, compared to the scale El-Al provide?

In other words:
* For TLV-BCN, the scale shows $0-$430, with the bar automatically placed at $340 for a "high strength".
* For ZRH-TLV, the scale shows $0-$380, with the bar automatically placed at $300 for a "high strength".

Note: El-Al represents the "strength" on a scale with 4 levels ("very low", "low", "high", "very high"?)


Any inputs are welcomed - thanks in advance.