[Xellath]

1. The code is still not indented properly.

2. Your menu should be callbacked.

new g_Callback[ 2 ];

public plugin_init( )
{
    g_Callback[ 0 ] = menu_makecallback( "MenuCallbackEnabled" );
    g_Callback[ 1 ] = menu_makecallback( "MenuCallbackDisabled" );
}

public USPMenu( id )
{
    new USP = menu_create( "\yChoose Your Type of \rUSP", "USPMenu_Handler" );
    
    menu_additem( USP, "\wNormal USP \r[$800]^n", "1", cs_get_user_money( id ) > get_pcvar_num( cost_Normal_USP ) ? g_Callback[ 0 ] : g_Callback[ 1 ] );
    menu_additem( USP, "\wReloaded USP \r[$5000]^n", "2", cs_get_user_money( id ) > get_pcvar_num( cost_Reloaded_USP ) ? g_Callback[ 0 ] : g_Callback[ 1 ] );
    
    menu_display( id, USP, 0 );
}

public MenuCallbackEnabled( id, menu, item )
{
    return ITEM_ENABLED;
}

public MenuCallbackDisabled( id, menu, item )
{
    return ITEM_DISABLED;
}