Much depends on what you mean by "etc...". By calling your data structure "%hash" (which isn't very descriptive) and stopping right when things got interesting (i.e., how do you handle multiple values that share the key "item"), you've left the problem in an ambiguous state. Part of advancing past newbyness is learning to drive out ambiguity when thinking through what you need to do.
Since in the data you've shown, several strings will end up sharing the "item" key, I suspect that you want individual anonymous hashes, one per group, each having a single "item" key. If this is true, then you want to parse the text into a structure that looks like
my $data = [
{
item => 'Athlon 4000+',
price => '300 euro',
...
},
{
item => 'Celeron 3000',
price => '200 euro',
...
},
...
];
Does this help?