Hi Martin
If you buy the plain coloured foils rounds, Hearts & Stars you will find them a lot cheaper than the printed ones (winnie the pooh etc etc) you will also find your wholesaler may sell unpackaged balloons to be cheaper still.
Foil balloons will hold Twisted designs in place but we always find if we are using a 260 model and want it to be held up we find if we attach it to four small 5" balloons inflated to 4" and tied together by the knots and tie the twisted model into the centre and then add the helium filled balloons (you will also need a weight to hold the helium balloon down which can be also tied into the centre knots but below the cluster
of four balloons)
an example of which on our website
http://www.balloonsandtunes.co.uk/gallery/Balloon-Bouquets-for-Tables/2005_0611_161525AA_teddy_bears_wedding_displaywas used for a wedding
Pam