Fruit cage just for the fruiting season

I have a 10 x 4 feet bed with autumn rasperries, a 10 x 4 feet bed with three blackcurrant bushes, a 10 x 4 bed with strawberries and a 10 x 4 bed with redcurrants and gooseberries.

My question is - what is the cheapest option to keep birds from eating their fill and leaving me with no fruit?

Can I construct a framework of netting and bamboo canes with pop bottles over the cane ends to drape the netting over and pegging the netting down to stop birds from hopping under?  Or do I have to go to the length of constructing permanent cages; adding to the expense of growing fruit?

I am thinking of netting the bushes as they come into bud for fruit but leaving the bushes open the rest of the year so birds can pick off any pests.

Thats basicly what i do.  I just use some enviromesh and old net curtains and  cover just before the fruit ripens and anchor it down with bricks.   Trick is to get the cover over just at the right time because the birds start taking the fruit before  its really ripe.   Its a bit of a pain crawling under to pick  the fruit  and sometimes the net blows off in the wind but its the easiest option .

I'm only 5'4" and do yoga so I'm quite flexible for crawling!

I've put in a line of 4 x8' posts, standing about 6.5' out of the ground, with blackberry, raspberry, and loganberry planted between them. On top of the posts I've got 3' timbers making a T at right angles to the line of posts. My plan is to stretch wire between the ends of the Ts. and when it's getting to fruit time to drape net over the wires and down to ground level, stapled to light battens, giving me a temporary cage I can stand up in...

will probably all collapse or blow away like all my other ideas...