Hi Segaboy - I think it would have been better to have started a new topic with a different title as some people may not be interested in "super bargain seeds" and could miss your post.
First, welcome to Down the Lane
Please could you tell us where you are as it might make a difference to the range of answers. I'm presuming you are in the UK.
Which beans are you talking about? French or Runner Beans are very frost sensitive and are not normally sown until about mid-April (from early May under cloche outdoors, depending on the weather) They can be grown in greenhouses/polytunnel if you have one and can be started off early. They do best when the weather is hot and sunny rather than a cold wet spring where they may sulk. Broad beans can be started about now in pots or direct outdoors - they don't climb so should not be tangled. To avoid damage to roots, both beans and peas should ideally be sown in individual pots rather than trays.
Peas - there are some winter hardy cultivars but again, way too soon to sow. From about mid-March for early varieties if conditions where you live are mild, main crop from about April/May.
To answer your question - given the cost of seed, I would simply bin (or compost) the seedlings and start again, preferably at a suitable time. As they are treated like annuals, it is best to encourage growth once they germinate rather than disrupt it with potting on and planting out. Personally, my crops do better when sown direct rather than starting in pots.